Open, standard protocols are the core of the Internet, some, such as http – the Hypertext Transfer Protocol, are well known, others less well known. Several of these would help smooth the flow of information, make the Internet easier to use, more secure, or enable solutions to be shared more easily if they were more widely known and used.
These are the ones described here.
XMPP – Chat or Instant Messaging
OTP – One Time Passwords
CalDAV – Calendar sharing
CardDav – Address book sharing
PGP – signing or encrypting emails.
LDAP – user account data and much more
Kerberos – Security
Sieve – Sorting email
IMAP – reading email
Mailing lists
WebRTC – video conferencing.
Mail – plus addressing.